1. Field of the Invention
The present invention relates in general to sensors and, in particular, to a network, sensor and method capable of using impulse radio technology to help monitor and/or control the environment within a building.
2. Description of Related Art
In a home, office or industrial environment, it would be desirable to let people better monitor and/or control the environment within a building. Unfortunately, to date there does not appear to be any sensor that effectively enables people to monitor and control the environment outside or within a building. For instance, most sensors (e.g., thermostats) are hard wired to a controller (e.g., heating/cooling controller) which can be problematical in that only a few hard-wired sensors are typically used to control the environment (e.g., temperature) within the entire building. In such a situation, it is common for one room or area of the building to be cold while another room or area of the building is hot. Another problem with hard-wired sensors is that there is a large expense to install these sensors.
To address the problems with hard-wired sensors, sensors that have a wireless interface with their controllers have been developed and sold. However, new problems have arisen with the use of wireless sensors because with standard radio transmissions there are often problematical xe2x80x9cdead zonesxe2x80x9d within a building that may interfere with the wireless link between the sensor and the controller. The xe2x80x9cdead zonesxe2x80x9d are caused by the closed structure of the building, which can make it difficult for a sensor attached to standard radio transmitter to maintain contact with a standard radio receiver attached to a controller. In particular, the standard radio signals sent from the standard radio transmitter attached to the sensor may not be able to penetrate a certain wall or floor within the building and as such may not reach the standard radio receiver attached to the controller. This is especially true if the sensor can be moved to different locations within the building.
The closed structure of the building may also cause xe2x80x9cmultipath interferencexe2x80x9d which can interfere with standard radio transmission between the sensor and the controller. Multipath interference is an error caused by the interference of a standard radio signal that has reached a standard radio receiver by two or more paths. Essentially, the standard radio receiver may not be able to demodulate the standard radio signal because the transmitted radio signal effectively cancels itself out by bouncing of walls and floors of the building before reaching the standard radio receiver. Accordingly, there has been a persistent need to overcome the shortcomings of traditional sensors by providing a network, sensor and method that can effectively monitor and/or control the environment within a building.
The present invention includes a network, sensor and method that can use impulse radio technology to help monitor and/or control the environment within a building. In particular, the network includes a sensor attached to a first impulse radio unit that is capable of transmitting an impulse radio signal containing sensor related information to a second impulse radio unit. The second impulse radio unit is attached to a control station that uses the sensor related information (e.g., environmental related information, safety related information or surveillance related information) to monitor and/or control the environment within a building. In one aspect of the present invention, the control system can better control and monitor the environment within the building because the sensor may be moved around within the building and reference impulse radio units may interact with the first impulse radio unit to enable the determination of the current position of the sensor.